Visual Acuity in Mentally Retarded Children Measured with the Forced-Preferential Looking Procedure and the Scolatest

Abstract

The forced-preferential looking test has been shown to be an accurate method for assessment of monocular grating acuity in mentally retarded children. The current study seeks to validate the procedure further by comparing the results between different groups of retarded patients and young children. Assessment was made with the forced-choice preferential looking procedure and Scolatest. Fourteen patients from an institution for retarded patients and 15 children from a pediatric hospital were examined. The results show that visual acuity estimation can be determined twice as often by the forced-preferential looking test than by Scolatest. Contrary to previous studies, the Snellen visual acuity was better than the grating visual acuity in both the retarded group and normal children.

• visual acuity
• mental retardation
• preferential looking
• Scolatest